﻿using System;
using System.Text;
using System.Net;
using System.IO;
using System.Threading;

public class HttpHelper
{
    #region 私有变量
//        private CookieContainer cc;
    private string contentType = "application/x-www-form-urlencoded";
    private string accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/x-silverlight, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, application/x-silverlight-2-b1, */*";
    private string userAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)";
    private Encoding encoding = Encoding.GetEncoding("utf-8");

    private string username = string.Empty;
    private string password = string.Empty;
    #endregion

    #region 属性
    /// <summary>
    /// Cookie容器
    /// </summary>
    public CookieContainer CookieContainer { get; set; }

    /// <summary>
    /// 获取网页源码时使用的编码
    /// </summary>
    /// <value></value>
    public Encoding Encoding
    {
        get
        {
            return encoding;
        }
        set
        {
            encoding = value;
        }
    }

    #endregion

    #region 构造函数
    /// <summary>
    /// Initializes a new instance of the <see cref="HttpHelper"/> class.
    /// </summary>
    public HttpHelper()
    {
        this.CookieContainer = new CookieContainer();
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="HttpHelper"/> class.
    /// </summary>
    /// <param name="cc">The cc.</param>
    public HttpHelper(CookieContainer cc)
    {
        this.CookieContainer = cc;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="HttpHelper"/> class.
    /// </summary>
    /// <param name="contentType">Type of the content.</param>
    /// <param name="accept">The accept.</param>
    /// <param name="userAgent">The user agent.</param>
    public HttpHelper(string contentType, string accept, string userAgent)
    {
        this.contentType = contentType;
        this.accept = accept;
        this.userAgent = userAgent;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="HttpHelper"/> class.
    /// </summary>
    /// <param name="cc">The cc.</param>
    /// <param name="contentType">Type of the content.</param>
    /// <param name="accept">The accept.</param>
    /// <param name="userAgent">The user agent.</param>
    public HttpHelper(CookieContainer cc, string contentType, string accept, string userAgent)
    {
        this.CookieContainer = cc;
        this.contentType = contentType;
        this.accept = accept;
        this.userAgent = userAgent;
    }
    #endregion

    #region 公共方法
    public void SetCredentials(string username, string password)
    {
        this.username = username;
        this.password = password;
    }

    /// <summary>
    /// 获取指定页面的HTML代码
    /// </summary>
    /// <param name="url">指定页面的路径</param>
    /// <param name="postData">回发的数据</param>
    /// <param name="isPost">是否以post方式发送请求</param>
    /// <param name="cookieContainer">Cookie集合</param>
    /// <returns></returns>
    public string GetHtml(string url, string postData, bool isPost, CookieContainer cookieContainer)
    {
        if (string.IsNullOrEmpty(postData))
        {
            return GetHtml(url, cookieContainer);
        }

        try
        {
            byte[] byteRequest = Encoding.Default.GetBytes(postData);

            HttpWebRequest httpWebRequest;
            httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
            httpWebRequest.CookieContainer = cookieContainer;
            httpWebRequest.ContentType = contentType;
            httpWebRequest.Referer = url;
            httpWebRequest.Accept = accept;
            httpWebRequest.UserAgent = userAgent;
            httpWebRequest.Method = isPost ? "POST" : "GET";
            httpWebRequest.ContentLength = byteRequest.Length;

            // http://www.douban.com/group/topic/5509228/
            // http://www.gnegg.ch/2006/09/lighttpd-net-httpwebrequest/
            // 为了解决 twitter post 的错误
            httpWebRequest.ServicePoint.Expect100Continue = false;

            if (!string.IsNullOrEmpty(this.username))
            {
                httpWebRequest.Credentials = new NetworkCredential(this.username, this.password);
            }

            Stream stream = httpWebRequest.GetRequestStream();
            stream.Write(byteRequest, 0, byteRequest.Length);
            stream.Close();

            HttpWebResponse httpWebResponse;
            httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            Stream responseStream = httpWebResponse.GetResponseStream();
            StreamReader streamReader = new StreamReader(responseStream, encoding);
            string html = streamReader.ReadToEnd();
            streamReader.Close();
            responseStream.Close();

            return html;
        }
        catch (Exception e)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine(DateTime.Now.ToString("HH:mm:ss ") + e.Message);
            Console.ForegroundColor = ConsoleColor.White;

            return string.Empty;
        }
    }

    /// <summary>
    /// 获取指定页面的HTML代码
    /// </summary>
    /// <param name="url">指定页面的路径</param>
    /// <param name="cookieContainer">Cookie集合</param>
    /// <returns></returns>
    public string GetHtml(string url, CookieContainer cookieContainer)
    {
        try
        {
            HttpWebRequest httpWebRequest;
            httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
            httpWebRequest.CookieContainer = cookieContainer;
            httpWebRequest.ContentType = contentType;
            httpWebRequest.Referer = url;
            httpWebRequest.Accept = accept;
            httpWebRequest.UserAgent = userAgent;
            httpWebRequest.Method = "GET";

            httpWebRequest.KeepAlive = false;

            HttpWebResponse httpWebResponse;
            httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            Stream responseStream = httpWebResponse.GetResponseStream();
            StreamReader streamReader = new StreamReader(responseStream, encoding);
            string html = streamReader.ReadToEnd();
            streamReader.Close();
            responseStream.Close();

            return html;
        }
        catch (Exception e)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine(DateTime.Now.ToString("HH:mm:ss ") + e.Message);
            Console.ForegroundColor = ConsoleColor.White;

            return string.Empty;
        }
    }

    /// <summary>
    /// 获取指定页面的HTML代码
    /// </summary>
    /// <param name="url">指定页面的路径</param>
    /// <returns></returns>
    public string GetHtml(string url)
    {
        return GetHtml(url, this.CookieContainer);
    }

    /// <summary>
    /// 获取指定页面的HTML代码
    /// </summary>
    /// <param name="url">指定页面的路径</param>
    /// <param name="postData">回发的数据</param>
    /// <param name="isPost">是否以post方式发送请求</param>
    /// <returns></returns>
    public string GetHtml(string url, string postData, bool isPost)
    {
        return GetHtml(url, postData, isPost, this.CookieContainer);
    }

    /// <summary>
    /// 获取一个随机延迟
    /// </summary>
    /// <returns></returns>
    private int GetDynamicDelay()
    {
        return 0;
        //return new Random(DateTime.Now.Millisecond).Next(2000);
    }
    #endregion
}
